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Underground Injection Control (UIC) Program Overview

The Oregon Department of Environmental Quality (ODEQ) issued a permit in June 2005 authorizing stormwater discharges to city-owned UICs. The permit protects groundwater through an aggressive stormwater management program, and uses stormwater as a resource to recharge groundwater and surface water. The City of Portland’s UIC Program has five goals:

Ensure that UICs are constructed, operated, and maintained in a manner that meets Water Pollution Control Facilities (WPCF) permit requirements and protects groundwater for use as a drinking water resource.

Use stormwater as a resource by facilitating long-term operation of stormwater facilities that support the natural hydrogeologic cycle, provide baseflow for surface waters, and contribute to normative stream flow conditions by reducing storm flow to piped sewer systems.

Emphasize management actions that prevent, minimize, and treat pollutants in stormwater before they can be discharged to a UIC.

Collect and evaluate stormwater data that are representative of the overall UIC system to verify groundwater protection and WPCF permit compliance and to identify where system improvements are needed.

Ensure that non-compliant UICs are identified, operated, modified, and/or decommissioned in a manner that brings them into compliance.

The UIC Program is organized into four main elements: System Management, System Monitoring, Evaluation and Response, and Corrective Actions. The UIC Management Plan (UICMP) describes the overall program and outlines how it will be implemented.

1) System Management. Includes a description of citywide best management practices (BMPs) implemented on an ongoing basis to prevent, minimize, and control pollutants in stormwater prior to discharge to a UIC. For example, the BMP category System Inventory and Assessment (SA) focuses on tracking, updating, and refining information related to the location and physical characteristics of existing and new public UICs.

Technical documents that support the System Management program element are:

2) System Monitoring. Includes required stormwater discharge monitoring and BMP monitoring. Data generated from monitoring demonstrates that UICs are operated in a manner that meets WPCF permit requirements and protects groundwater as a drinking water resource.

Technical documents that support the System Monitoring program element are:

3) Evaluation and Response. Uses data generated by the System Management and System Monitoring program elements to identify UICs that may not comply with permit requirements. This program element establishes the criteria and processes necessary to determine UIC compliance, address data gaps, prioritize evaluation and response actions, and demonstrate groundwater protection. UICs identified as non-compliant are addressed in the Corrective Action program element. Figure 5-2 in the UICMP is a flow chart of the evaluation and response process.

In addition to complying with the WPCF permit, the UIC Program and UICMP must meet the requirements of Oregon Administration Rules (OAR) 340-044-0018(3)(b)(C). These requirements specify that municipalities with 50 or more UICs must prepare and implement a written stormwater management plan that includes a systemwide assessment, system controls, monitoring, and a plan for record keeping and reporting.